Reverse action switch control



Oct. 19, 1948. v BENTLEY 2,451,905

REVERSE ACTION SWITCH CONTROL Filed. Dec. 5, 1947 'INVENTOR. l- ROBERT H. BENTLEY 69 his aiI-ornqy wws Patented @ct. 19,.1948

.REVERSE ACTION SWITCH CONTROL Robert H. Bentley, Hartford, Conn, assignorr to- The Arrow Hart & Hegeman Electric Com.- pany, Hartford, 001111., a corporation of'Conenecticut' Application December 3, 1947, SerialiNo. 789,344

9 Claims. (01. ii-110) This invention relates to operating mechanism for electric switches. More particularly the in vention relates to operating mechanism which can be combined with a conventional simple. form of switch for the purpose of. converting that switch from normally closed to normally opened condition without any change in the switch structure.

Certain forms of switches are made by manufacturers with their contacts normally biased to closed position. On some occasions conditions require that the circuit be normally open. In such instances the manufacturers could make a different switch; but that would. require considerable expense in designing'and in forming tools and dies as well as other expenses. Thus, in order to utilize the switches for whichthe manufacturers already have parts or are equippedto manufacture, the present inventionprovides an operating mechanism which can be applied to the manufacturers usual formo'f switch (whose con.--

tacts are normally pressed closed) and which without change in the switch structure will con vert the switch into anormally open switch structure. The objects and advantages-of the invention will become apparent as it is described in;

but with the Fig. 4 is an exploded perspectivefview of the parts of the operating mechanism, except the frame. i

The movable parts of the. invention are mounted upon a frame it which may be stamped. from sheet metal to provide parallel sides bent down from a flat top. End portions may also be bent to provide like parallel: fiat side portionsqn 24 joined-at one; edge near the. mid-portionlabwa transverse bar or connecting: portion-126:; :This operating. member 20. is pivotally mountedrini the frame .llLby a fixed pivot; pin.'29- passing; through aligned pivot-pinholes 23 provideddnieach ofithe. sides 22; 24 near one end. Neartheoppositeend aligned apertures Ziare-provided-in each ofi the sides 22 and 24 -to. receive? the'tr-unnions. J4; of. the operatingbar I2. r

Another. operating. member 30, which-ion con-r venient. reference will be called the-secondary; 0P7 crating member, is pivotallymounted Oll'rfiwfiXBdj pin or. pivot. 3 I mounted transverselyr in; the, side, of the frame paralleltopivot pin 29;. Thissop erating member 30 may be stamped from sheet metal and comprises-parallel side plates 32'and- 34; whose longitudinal. edges are joined. at .one; end bya transverse connecting bar portion: 33; Aligned. pivot-pin apertures- 35- in the. sides 32; 34. are providedior'the fixed pivoti-pin; 3|; Ina order to cause a rocking of the-secondary ORGIT-Y ating; member about the fixed; pivot 3-1; a loose: pivotalor pin andlslot connection is providedrbetween the primar and thev secondary operating: members in the following manner. In the ends of the side plates 32 and 34-, are alignedlongitudinal slots 36-whicht receive cylindrical pivot;

I lugs or. stub-pins 28; mounted on and extendT.-.-

down perpendicularly to the top in substantially parallelism to each other.

Projecting through a slot in the top frame is a stamped sheet metal operating bar 12 which may be of any suitable shape but in the embodiment illustrated is of substantially rectangular form and has trunnions M extending in opposite directions from the bottom or interior edge. Trunnions l4 engage with a primary operatin member 23 as will hereinafter be described.

An operating member 20, which for convenient reference, will be called the primary operating member is or may be stamped from sheet metal ingfrom the interior'faces of the sides:22 andiM: of the primary operating member zllnthese pivot lugs 28- being coaxial and: extending:toward, each other. In order to permit pivotal:motion ofthe:

primary'operating member; curved slots 21 are.

provided in the upper edges'of the sidesn; 24".. These slots accommodate the fixedz pivotpinx 3| of thersecondary operatingrmember whemthe lattermoves.

From the foregoing it may now: be observed that asthe primary; operating, member 20? is:- moved from the" position, of; Fig} 1; by pressing:

upon the operating bar l2, the primary operating member will pivot about its fixed pivot 29. This carries in clockwise direction the pivot lugs 28 which slidably engage in the end slots 36 of the secondary operating member. This clockwise movement of the primary operating member thus causes counterclockwise movement of the secondary operating member about its fixed pivot 3|. Thus, the transverse bar portion 33 of the secondary operating member will rise as the primary operating member is moved clockwise. The transverse portion 33 is in engagement with the operating button 40 of a conventional switch 42.

Since the precise structure of the switch 42 forms no part of this invention, its details are not particularly illustrated. Any sort of switch mechanism in which an operating button will cause operation of contacts when depressed (as in Fig. 1) from an upper position (as in Fig. 2) into which it heretofore has been normally biased, may be operated by my novel operating mechanism. (See for example my Patent 2,366,474, patented January 2, 1945, in which an operating plunger is held elevated normally by spring pressure which at the same time holds contacts closed.)

In order to maintain the parts in the position illustrated in Fig. 1, normally, with the operating button 40 of the switch depressed, I have provided an expanding coiled compression spring 44 between the top of the frame and the secondary operating member 30. To hold the top of the spring in the desired location, a hole 46 is punched in the top of the casing with its edges pressed inwardly around the hole to form a neck coaxial with the spring axis. The other end of the spring seats against a strut 50 which is punched to provide a neck, as just described, to locate the other spring end. The strut may be stamped in substantially square form from sheet metal with lugs 52 laterally extending in opposite directions to fit in aligned slots 31 formed in the side plates 32 and 34 of the secondary operating member. Thus, the spring M tends to move the secondary operating member in a, clockwise direction around the pivot 3l which exerts a counterclockwise pressure against the pivot lugs 28 on the primar operating member and -'thus urges the primary operating member counterclockwise into the position of Fig. 1.

By means of this operating mechanism a conventional switch of simple form in which the contacts are normally spring-pressed closed may be converted into a switch in which the same contacts of the same switch mechanism are normally held open. It is necessary of course in that case that the force of the spring 44 as it is exerted through the combination of parts illustrated and described be sufficient to overcome the upward pressure of the operating button 40 of the switch 42.

Thus a manufacturer need only carry in stock one type of switch with which he'can readily combine the operating mechanism of the present invention when a customer prefers to have a normally open switch. 7

Many modifications within the scope of my invention will occur to those skilled in the art. Therefore I do not limit the invention to the precise form of the embodiment illustrated.

What I claim is:

1. In combination, an electric switch having an operating button normally biased outwardly, operating mechanism to hold said button .pressed in against its bias comprising a frame, a fixed pivot mounted in said f am a member moun ed on Number said pivot, a second fixed pivot, a second member mounted on said second pivot, a loose pivotal connection between said second member and said first member between said pivots, spring means between said frame and said second member acting on said second member on the opposite side of its fixed pivot from said loose pivotal connection to cause said second member normally to depress said operating button, and means engageable to move said first member in opposition to said spring means.

2. In combination, an electric switch having an operating button normally biased outwardly, operating mechanism fixedly related to the switch for holding said button pressed in against said bias, comprising a fixed pivot, a member mounted on said pivot, a second fixed pivot, a second member mounted on said second pivot, a connection between said first and second members causing said second member to pivot in a direction opposite the direction of movement of the first memher, said second member being engaged with said button to control its movement and means biasing said members in direction to depress said button.

3. The combination claimed in claim 2 having an operating bar pivotally connected to said first member to move the latter.

4. The combination claimed in claim 2 wherein the connection between the first and second members is a pin and slot connection.

5. The combination claimed in claim 2 wherein the connection between said first and second members lies between said fixed pivots.

6. The combination claimed in claim 5 having an operating bar pivotally connected to said first member at a point remote from its pivot to give increased leverage.

7. The combination claimed in claim 2 wherein the biasing means is a spring which acts on said second member between its pivot and the point of engagement with said button.

8. The combination claimed in claim 2 wherein the operating mechanism is mounted on a frame and the frame is attach-ed to the switch to form a unit and to locate the mechanism in fixed relation to the switch.

9. The combination claimed in claim 8 wherein the second member has parallel side plates, a spring strut between said plates, said biasing means comprising a spring pressing on said strut and against said frame.

ROBERT H. BENTLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 2,236,680 Fry Apr. 1, 1941 

